Two row, angular contact ball bearings include a first race with axially inwardly facing ball pathways that engage the outside of the ball rows, and a second race with axially outwardly facing ball pathways that engage the inside of the ball rows. The most common type of two row ball bearing used as a vehicle wheel bearing puts the axially inwardly facing pathways on the inner race, so that the contact angles of the two ball rows converge and intersect on a plane midway between the ball rows. This provides a stiffer bearing than the alternative configuration, with divergent, non intersecting ball row contact angles. It is also most common in a vehicle wheel bearing to make one of the axially inwardly facing pathways separable or removable. This is done so that the second ball row can be loaded with the theoretical maximum number of balls as will fit between the pathways, a so called full complement. A good example of such a wheel bearing may be seen in co assigned U.S. Pat. No. 4,179,167 to Lura et al. Different bearing designs retain the separable pathway to the bearing in different ways, but the basic assembly method and reason for it are the same.
Another possible two row, angular contact ball bearing design has all four pathways fully integrally ground with the races. An example may be seen in U.S. Pat. No. 4,069,435 to Wannerskog et al. Integrally grinding all pathways eliminates the separable pathway and its retention structure, but limits load capacity, since the second installed ball row cannot be full complement. The first installed row can be, since it is installed before there is any access obstruction from the outer race. A smaller ball count in the second ball row is inevitable, however, because the only way to install it is to radially displace and tilt the races relative to one another, thereby widening the radial space between the races far enough to insert the balls. That installation space is only long enough to insert about half the number of balls. The balls are caged or separated within the two rows in two basic ways. Each ball row may be given its own, dedicated separator, as in the '435 patent. In that case, the first row has its separator installed first, and the second row last. The balls in the second row are spaced out evenly after loading, and a comb like cage with all open pockets is pushed axially in between the races and snapped over the balls. It is also known to align the balls in both rows in axially opposed pairs, and then install a single piece separator that has pockets long enough to reach and snap over both rows. This arrangement, of course, limits the first ball row count to the same number as the second row, which greatly limits load capacity.